<?php
/*
* Copyright (c) 2003-2011, CKSource - Frederico Knabben. All rights reserved.
* For licensing, see LICENSE.html or http://ckeditor.com/license
*/

/**
 * \brief CKEditor class that can be used to create editor
 * instances in PHP pages on server side.
 * @see http://ckeditor.com
 *
 * Sample usage:
 * @code
 * $CKEditor = new CKEditor();
 * $CKEditor->editor("editor1", "<p>Initial value.</p>");
 * @endcode
 */
class CKEditor
{
    /**
     * The version of %CKEditor.
     */
    const version = '3.5.2';
    /**
     * A constant string unique for each release of %CKEditor.
     */
    const timestamp = 'B1GG4Z6';

    /**
     * URL to the %CKEditor installation directory (absolute or relative to document root).
     * If not set, CKEditor will try to guess it's path.
     *
     * Example usage:
     * @code
     * $CKEditor->basePath = '/ckeditor/';
     * @endcode
     */
    public $basePath;
    /**
     * An array that holds the global %CKEditor configuration.
     * For the list of available options, see http://docs.cksource.com/ckeditor_api/symbols/CKEDITOR.config.html
     *
     * Example usage:
     * @code
     * $CKEditor->config['height'] = 400;
     * // Use @@ at the beggining of a string to ouput it without surrounding quotes.
     * $CKEditor->config['width'] = '@@screen.width * 0.8';
     * @endcode
     */
    public $config = array();
    /**
     * A boolean variable indicating whether CKEditor has been initialized.
     * Set it to true only if you have already included
     * &lt;script&gt; tag loading ckeditor.js in your website.
     */
    public $initialized = false;
    /**
     * Boolean variable indicating whether created code should be printed out or returned by a function.
     *
     * Example 1: get the code creating %CKEditor instance and print it on a page with the "echo" function.
     * @code
     * $CKEditor = new CKEditor();
     * $CKEditor->returnOutput = true;
     * $code = $CKEditor->editor("editor1", "<p>Initial value.</p>");
     * echo "<p>Editor 1:</p>";
     * echo $code;
     * @endcode
     */
    public $returnOutput = false;
    /**
     * An array with textarea attributes.
     *
     * When %CKEditor is created with the editor() method, a HTML &lt;textarea&gt; element is created,
     * it will be displayed to anyone with JavaScript disabled or with incompatible browser.
     */
    public $textareaAttributes = array("rows" => 8, "cols" => 60);
    /**
     * A string indicating the creation date of %CKEditor.
     * Do not change it unless you want to force browsers to not use previously cached version of %CKEditor.
     */
    public $timestamp = "B1GG4Z6";
    /**
     * An array that holds event listeners.
     */
    private $events = array();
    /**
     * An array that holds global event listeners.
     */
    private $globalEvents = array();

    /**
     * Main Constructor.
     *
     * @param $basePath (string) URL to the %CKEditor installation directory (optional).
     */
    function __construct($basePath = null)
    {
        if (!empty($basePath)) {
            $this->basePath = $basePath;
        }
    }

    /**
     * Creates a %CKEditor instance.
     * In incompatible browsers %CKEditor will downgrade to plain HTML &lt;textarea&gt; element.
     *
     * @param $name (string) Name of the %CKEditor instance (this will be also the "name" attribute of textarea element).
     * @param $value (string) Initial value (optional).
     * @param $config (array) The specific configurations to apply to this editor instance (optional).
     * @param $events (array) Event listeners for this editor instance (optional).
     *
     * Example usage:
     * @code
     * $CKEditor = new CKEditor();
     * $CKEditor->editor("field1", "<p>Initial value.</p>");
     * @endcode
     *
     * Advanced example:
     * @code
     * $CKEditor = new CKEditor();
     * $config = array();
     * $config['toolbar'] = array(
     *     array( 'Source', '-', 'Bold', 'Italic', 'Underline', 'Strike' ),
     *     array( 'Image', 'Link', 'Unlink', 'Anchor' )
     * );
     * $events['instanceReady'] = 'function (ev) {
     *     alert("Loaded: " + ev.editor.name);
     * }';
     * $CKEditor->editor("field1", "<p>Initial value.</p>", $config, $events);
     * @endcode
     */
    public function editor($name, $value = "", $config = array(), $events = array())
    {
        $attr = "";
        foreach ($this->textareaAttributes as $key => $val) {
            $attr .= " " . $key . '="' . str_replace('"', '&quot;', $val) . '"';
        }
        $out = "<textarea name=\"" . $name . "\"" . $attr . ">" . htmlspecialchars($value) . "</textarea>\n";
        if (!$this->initialized) {
            $out .= $this->init();
        }

        $_config = $this->configSettings($config, $events);

        $js = $this->returnGlobalEvents();
        if (!empty($_config))
            $js .= "CKEDITOR.replace('" . $name . "', " . $this->jsEncode($_config) . ");";
        else
            $js .= "CKEDITOR.replace('" . $name . "');";

        $out .= $this->script($js);

        if (!$this->returnOutput) {
            print $out;
            $out = "";
        }

        return $out;
    }

    /**
     * Replaces a &lt;textarea&gt; with a %CKEditor instance.
     *
     * @param $id (string) The id or name of textarea element.
     * @param $config (array) The specific configurations to apply to this editor instance (optional).
     * @param $events (array) Event listeners for this editor instance (optional).
     *
     * Example 1: adding %CKEditor to &lt;textarea name="article"&gt;&lt;/textarea&gt; element:
     * @code
     * $CKEditor = new CKEditor();
     * $CKEditor->replace("article");
     * @endcode
     */
    public function replace($id, $config = array(), $events = array())
    {
        $out = "";
        if (!$this->initialized) {
            $out .= $this->init();
        }

        $_config = $this->configSettings($config, $events);

        $js = $this->returnGlobalEvents();
        if (!empty($_config)) {
            $js .= "CKEDITOR.replace('" . $id . "', " . $this->jsEncode($_config) . ");";
        } else {
            $js .= "CKEDITOR.replace('" . $id . "');";
        }
        $out .= $this->script($js);

        if (!$this->returnOutput) {
            print $out;
            $out = "";
        }

        return $out;
    }

    /**
     * Replace all &lt;textarea&gt; elements available in the document with editor instances.
     *
     * @param $className (string) If set, replace all textareas with class className in the page.
     *
     * Example 1: replace all &lt;textarea&gt; elements in the page.
     * @code
     * $CKEditor = new CKEditor();
     * $CKEditor->replaceAll();
     * @endcode
     *
     * Example 2: replace all &lt;textarea class="myClassName"&gt; elements in the page.
     * @code
     * $CKEditor = new CKEditor();
     * $CKEditor->replaceAll( 'myClassName' );
     * @endcode
     */
    public function replaceAll($className = null)
    {
        $out = "";
        if (!$this->initialized) {
            $out .= $this->init();
        }

        $_config = $this->configSettings();

        $js = $this->returnGlobalEvents();
        if (empty($_config)) {
            if (empty($className)) {
                $js .= "CKEDITOR.replaceAll();";
            } else {
                $js .= "CKEDITOR.replaceAll('" . $className . "');";
            }
        } else {
            $classDetection = "";
            $js .= "CKEDITOR.replaceAll( function(textarea, config) {\n";
            if (!empty($className)) {
                $js .= "	var classRegex = new RegExp('(?:^| )' + '" . $className . "' + '(?:$| )');\n";
                $js .= "	if (!classRegex.test(textarea.className))\n";
                $js .= "		return false;\n";
            }
            $js .= "	CKEDITOR.tools.extend(config, " . $this->jsEncode($_config) . ", true);";
            $js .= "} );";

        }

        $out .= $this->script($js);

        if (!$this->returnOutput) {
            print $out;
            $out = "";
        }

        return $out;
    }

    /**
     * Adds event listener.
     * Events are fired by %CKEditor in various situations.
     *
     * @param $event (string) Event name.
     * @param $javascriptCode (string) Javascript anonymous function or function name.
     *
     * Example usage:
     * @code
     * $CKEditor->addEventHandler('instanceReady', 'function (ev) {
     *     alert("Loaded: " + ev.editor.name);
     * }');
     * @endcode
     */
    public function addEventHandler($event, $javascriptCode)
    {
        if (!isset($this->events[$event])) {
            $this->events[$event] = array();
        }
        // Avoid duplicates.
        if (!in_array($javascriptCode, $this->events[$event])) {
            $this->events[$event][] = $javascriptCode;
        }
    }

    /**
     * Clear registered event handlers.
     * Note: this function will have no effect on already created editor instances.
     *
     * @param $event (string) Event name, if not set all event handlers will be removed (optional).
     */
    public function clearEventHandlers($event = null)
    {
        if (!empty($event)) {
            $this->events[$event] = array();
        } else {
            $this->events = array();
        }
    }

    /**
     * Adds global event listener.
     *
     * @param $event (string) Event name.
     * @param $javascriptCode (string) Javascript anonymous function or function name.
     *
     * Example usage:
     * @code
     * $CKEditor->addGlobalEventHandler('dialogDefinition', 'function (ev) {
     *     alert("Loading dialog: " + ev.data.name);
     * }');
     * @endcode
     */
    public function addGlobalEventHandler($event, $javascriptCode)
    {
        if (!isset($this->globalEvents[$event])) {
            $this->globalEvents[$event] = array();
        }
        // Avoid duplicates.
        if (!in_array($javascriptCode, $this->globalEvents[$event])) {
            $this->globalEvents[$event][] = $javascriptCode;
        }
    }

    /**
     * Clear registered global event handlers.
     * Note: this function will have no effect if the event handler has been already printed/returned.
     *
     * @param $event (string) Event name, if not set all event handlers will be removed (optional).
     */
    public function clearGlobalEventHandlers($event = null)
    {
        if (!empty($event)) {
            $this->globalEvents[$event] = array();
        } else {
            $this->globalEvents = array();
        }
    }

    /**
     * Prints javascript code.
     *
     * @param string $js
     */
    private function script($js)
    {
        $out = "<script type=\"text/javascript\">";
        $out .= "//<![CDATA[\n";
        $out .= $js;
        $out .= "\n//]]>";
        $out .= "</script>\n";

        return $out;
    }

    /**
     * Returns the configuration array (global and instance specific settings are merged into one array).
     *
     * @param $config (array) The specific configurations to apply to editor instance.
     * @param $events (array) Event listeners for editor instance.
     */
    private function configSettings($config = array(), $events = array())
    {
        $_config = $this->config;
        $_events = $this->events;

        if (is_array($config) && !empty($config)) {
            $_config = array_merge($_config, $config);
        }

        if (is_array($events) && !empty($events)) {
            foreach ($events as $eventName => $code) {
                if (!isset($_events[$eventName])) {
                    $_events[$eventName] = array();
                }
                if (!in_array($code, $_events[$eventName])) {
                    $_events[$eventName][] = $code;
                }
            }
        }

        if (!empty($_events)) {
            foreach ($_events as $eventName => $handlers) {
                if (empty($handlers)) {
                    continue;
                } else if (count($handlers) == 1) {
                    $_config['on'][$eventName] = '@@' . $handlers[0];
                } else {
                    $_config['on'][$eventName] = '@@function (ev){';
                    foreach ($handlers as $handler => $code) {
                        $_config['on'][$eventName] .= '(' . $code . ')(ev);';
                    }
                    $_config['on'][$eventName] .= '}';
                }
            }
        }

        return $_config;
    }

    /**
     * Return global event handlers.
     */
    private function returnGlobalEvents()
    {
        static $returnedEvents;
        $out = "";

        if (!isset($returnedEvents)) {
            $returnedEvents = array();
        }

        if (!empty($this->globalEvents)) {
            foreach ($this->globalEvents as $eventName => $handlers) {
                foreach ($handlers as $handler => $code) {
                    if (!isset($returnedEvents[$eventName])) {
                        $returnedEvents[$eventName] = array();
                    }
                    // Return only new events
                    if (!in_array($code, $returnedEvents[$eventName])) {
                        $out .= ($code ? "\n" : "") . "CKEDITOR.on('" . $eventName . "', $code);";
                        $returnedEvents[$eventName][] = $code;
                    }
                }
            }
        }

        return $out;
    }

    /**
     * Initializes CKEditor (executed only once).
     */
    private function init()
    {
        static $initComplete;
        $out = "";

        if (!empty($initComplete)) {
            return "";
        }

        if ($this->initialized) {
            $initComplete = true;
            return "";
        }

        $args = "";
        $ckeditorPath = $this->ckeditorPath();

        if (!empty($this->timestamp) && $this->timestamp != "%" . "TIMESTAMP%") {
            $args = '?t=' . $this->timestamp;
        }

        // Skip relative paths...
        if (strpos($ckeditorPath, '..') !== 0) {
            $out .= $this->script("window.CKEDITOR_BASEPATH='" . $ckeditorPath . "';");
        }

        $out .= "<script type=\"text/javascript\" src=\"" . $ckeditorPath . 'ckeditor.js' . $args . "\"></script>\n";

        $extraCode = "";
        if ($this->timestamp != self::timestamp) {
            $extraCode .= ($extraCode ? "\n" : "") . "CKEDITOR.timestamp = '" . $this->timestamp . "';";
        }
        if ($extraCode) {
            $out .= $this->script($extraCode);
        }

        $initComplete = $this->initialized = true;

        return $out;
    }

    /**
     * Return path to ckeditor.js.
     */
    private function ckeditorPath()
    {
        if (!empty($this->basePath)) {
            return $this->basePath;
        }

        /**
         * The absolute pathname of the currently executing script.
         * Note: If a script is executed with the CLI, as a relative path, such as file.php or ../file.php,
         * $_SERVER['SCRIPT_FILENAME'] will contain the relative path specified by the user.
         */
        if (isset($_SERVER['SCRIPT_FILENAME'])) {
            $realPath = dirname($_SERVER['SCRIPT_FILENAME']);
        } else {
            /**
             * realpath - Returns canonicalized absolute pathname
             */
            $realPath = realpath('./');
        }

        /**
         * The filename of the currently executing script, relative to the document root.
         * For instance, $_SERVER['PHP_SELF'] in a script at the address http://example.com/test.php/foo.bar
         * would be /test.php/foo.bar.
         */
        $selfPath = dirname($_SERVER['PHP_SELF']);
        $file = str_replace("\\", "/", __FILE__);

        if (!$selfPath || !$realPath || !$file) {
            return "/ckeditor/";
        }

        $documentRoot = substr($realPath, 0, strlen($realPath) - strlen($selfPath));
        $fileUrl = substr($file, strlen($documentRoot));
        $ckeditorUrl = str_replace("ckeditor_php5.php", "", $fileUrl);

        return $ckeditorUrl;
    }

    /**
     * This little function provides a basic JSON support.
     * http://php.net/manual/en/function.json-encode.php
     *
     * @param mixed $val
     * @return string
     */
    private function jsEncode($val)
    {
        if (is_null($val)) {
            return 'null';
        }
        if ($val === false) {
            return 'false';
        }
        if ($val === true) {
            return 'true';
        }
        if (is_scalar($val)) {
            if (is_float($val)) {
                // Always use "." for floats.
                $val = str_replace(",", ".", strval($val));
            }

            // Use @@ to not use quotes when outputting string value
            if (strpos($val, '@@') === 0) {
                return substr($val, 2);
            } else {
                // All scalars are converted to strings to avoid indeterminism.
                // PHP's "1" and 1 are equal for all PHP operators, but
                // JS's "1" and 1 are not. So if we pass "1" or 1 from the PHP backend,
                // we should get the same result in the JS frontend (string).
                // Character replacements for JSON.
                static $jsonReplaces = array(array("\\", "/", "\n", "\t", "\r", "\b", "\f", '"'),
                    array('\\\\', '\\/', '\\n', '\\t', '\\r', '\\b', '\\f', '\"'));

                $val = str_replace($jsonReplaces[0], $jsonReplaces[1], $val);
                if (strtoupper(substr($val, 0, 9)) == 'CKEDITOR.') {
                    return $val;
                }

                return '"' . $val . '"';
            }
        }
        $isList = true;
        for ($i = 0, reset($val); $i < count($val); $i++, next($val)) {
            if (key($val) !== $i) {
                $isList = false;
                break;
            }
        }
        $result = array();
        if ($isList) {
            foreach ($val as $v) $result[] = $this->jsEncode($v);
            return '[ ' . join(', ', $result) . ' ]';
        } else {
            foreach ($val as $k => $v) $result[] = $this->jsEncode($k) . ': ' . $this->jsEncode($v);
            return '{ ' . join(', ', $result) . ' }';
        }
    }
}
